Casing centralizer

Abstract

The utility model relates to the technical field of oil extraction and well cementation, in particular to a casing centralizer which comprises two end rings which are symmetrically arranged up and down, each end ring is composed of two semi-rings, one ends of the two semi-rings are hinged through a hinge, the other ends of the two semi-rings are fixedly provided with a locking assembly, and a plurality of rib plate assemblies which are distributed in an annular array mode are fixedly arranged between the two end rings. The rib plate assembly comprises fixing columns fixedly connected to the outer walls of the two end rings, rib plates are installed on the two fixing columns, rolling units are installed on the inner sides, close to the middle positions, of the rib plates, and the rolling units protrude out of the surfaces of the rib plates. According to the casing centralizer, the rolling units are arranged on the inner sides of the rib plates, and the rolling units protrude out of the surfaces of the rib plates, so that when the casing centralizer is used, the rolling units on the rib plates can make contact with the well wall to form a rolling effect, friction between the rib plates and the well wall can be reduced, the purpose of reducing abrasion is achieved, the moving resistance of a casing can be reduced, and the service life of the casing is prolonged. And the service life is long.

Description

Technical Field

[0001] This utility model relates to the field of oil well cementing technology, specifically a casing centralizer. Background Technology

[0002] Due to complex and variable geological conditions, such as formation tilt, differences in rock hardness, and various external forces during drilling operations, casing is prone to tilting, twisting, or displacement in the wellbore. These problems can disrupt the stability of the oil well and affect oil extraction efficiency. Therefore, casing centralizers are needed to ensure the casing remains centered in the wellbore and guarantee smooth oil extraction. However, existing casing centralizers have the following problems: 1. During use, the ribs slide against the wellbore, resulting in significant wear and tear on the ribs, making them prone to damage, and also increasing resistance during movement; 2. The ribs and end rings are a single unit, making them unsuitable for wellbore sizes and resulting in poor adaptability; 3. The end rings are also a single unit, requiring a slip-fit ​​installation onto the casing, which is inconvenient. Utility Model Content

[0003] In view of the shortcomings of the existing technology, this utility model provides a casing centralizer, which solves the technical problems of high wear, poor adaptability and inconvenient installation of the existing casing centralizer.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a sleeve straightener, comprising two end rings arranged symmetrically at the top and bottom, each end ring being composed of two half rings, one end of each half ring being hinged by a hinge and the other end being fixed with a locking component, and a plurality of rib plate components arranged in a ring array being fixed between the two end rings.

[0005] The stiffener assembly includes fixed posts fixed to the outer walls of two end rings, with stiffeners installed on the two fixed posts. A rolling unit is installed on the inner side of the stiffener near the middle position, and the rolling unit protrudes from the surface of the stiffener.

[0006] Preferably, a second spring is fitted on the outer wall of the fixing column between the end ring and the stiffening plate, a baffle is fitted on one end of the fixing column, and a nut threaded onto the fixing column is provided on one side of the baffle.

[0007] Preferably, the stiffener is an outwardly convex arc-shaped structure.

[0008] Preferably, the rolling unit includes two fixing blocks fixed to the inner wall of the rib plate, a screw is fixed on the fixing block, and fixing plates that fit against the inner wall of the rib plate are sleeved at both ends of the screw. Nuts are also threaded to both ends of the screw. Multiple rollers that are equidistantly distributed are rotatably connected between the two fixing plates, and the multiple rollers are respectively located in multiple through holes opened on the side wall of the rib plate.

[0009] Preferably, the locking assembly includes a fixed buckle fixed to one of the end rings and two locking buckles fixed to the other end ring. A spring is installed inside the fixed buckle, and pins are movably connected to both ends of the spring. A lever is fixed to the lever and is located in a movable hole on the fixed buckle. One end of the lever is inserted into a lock hole on the locking buckle.

[0010] Preferably, the width of the stiffener gradually decreases from the middle to both ends.

[0011] By employing the above technical solution, this utility model provides a casing straightener, which has at least the following beneficial effects:

[0012] 1. This casing centralizer has rolling units set inside the rib plate, and the rolling units protrude from the surface of the rib plate. In use, the rolling units on the rib plate will contact the well wall and form a rolling action, which can reduce the friction between the rib plate and the well wall, thereby reducing wear and reducing the resistance of casing movement. It also has the advantage of long service life.

[0013] 2. This casing centralizer, by setting a spring two on the fixed rod, allows the stiffening plate to be elastically connected to the outside of the end ring through the spring two. This ensures that it can fully contact the well wall in wells of different sizes, ensuring that the casing is always in the centered position. It can adapt to different well sizes and has the advantage of strong adaptability.

[0014] 3. This sleeve centralizer divides the end ring into two half-rings. During installation, the two half-rings can be separated. It can be installed by either slipping the half-rings onto the sleeve or by directly separating the half-rings and installing them on the sleeve, which has the advantage of simple installation. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of the present invention, form part of this application:

[0016] Figure 1 This is a three-dimensional structural schematic diagram of the present utility model from an overall perspective.

[0017] Figure 2 This is a three-dimensional structural diagram of the present utility model from a second overall perspective;

[0018] Figure 3 This is a schematic diagram of the disassembled stiffener assembly of this utility model;

[0019] Figure 4 This is a schematic diagram of the structure of the rolling unit of this utility model;

[0020] Figure 5 This is a partial cross-sectional structural diagram of the locking unit of this utility model.

[0021] Figure label:

[0022] 1. End ring; 2. Hinge; 3. Locking assembly; 301. Fixing buckle; 302. Spring 1; 303. Pin; 304. Toggle block; 305. Locking buckle; 4. Rib plate assembly; 401. Fixing post; 402. Rib plate; 403. Spring 2; 404. Baffle plate; 405. Nut; 406. Rolling unit; 4061. Fixing block; 4062. Screw; 4063. Nut; 4064. Fixing plate; 4065. Roller. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] In oil drilling, casing is a key component connecting the wellhead to the oil reservoir. Its main functions are to reinforce the wellbore, prevent wellbore collapse, and provide a passage for subsequent oil production, water injection, and other operations.

[0025] Due to the technical shortcomings of existing technologies, such as high wear and tear, poor adaptability, and inconvenient installation, please refer to... Figures 1-5 This embodiment provides a casing centralizer that reduces friction between the stiffener plate 402 and the well wall, thereby reducing wear and reducing resistance to casing movement. The centralizer includes two symmetrically arranged end rings 1, each consisting of two semi-rings. One end of each semi-ring is hinged by a hinge 2, and the other end is fixed with a locking assembly 3. Multiple stiffener plate assemblies 4 arranged in a ring array are fixed between the two end rings 1. The hinge 2 and locking assembly 3 enable quick assembly and disassembly of the end rings 1, facilitating on-site installation and maintenance. The evenly distributed stiffener plates 402 provide symmetrical and stable support, ensuring better centering of the centralizer within the casing and reducing eccentric wear. In use, the entire assembly is fitted onto the casing using the upper and lower end rings 1. Then, when in the wellbore, the contact between the stiffener plates 402 and the well wall keeps the casing in a centered position.

[0026] Traditional centralizers with 402 stiffeners typically have fixed, rigid contact plates. Friction with the wellbore is primarily sliding, leading to severe wear and high resistance, significantly increasing the difficulty of casing movement. For solutions to this problem, please refer to... Figure 3 and Figure 4The stiffener assembly 4 includes fixed posts 401 fixed to the outer walls of two end rings 1. Stiffeners 402 are installed on the two fixed posts 401. A rolling unit 406 is installed on the inner side of the stiffener 402 near the middle position. The rolling unit 406 protrudes from the surface of the stiffener 402. By setting the rolling unit 406 on the inner side of the stiffener 402 and making the rolling unit 406 protrude from the surface of the stiffener 402, the rolling unit 406 on the stiffener 402 will contact the well wall and form a rolling action during use, which can reduce the friction between the stiffener 402 and the well wall, thereby reducing wear and reducing the resistance of casing movement.

[0027] Traditional casing centralizers have a single integrated structure between the stiffener plate 402 and the end ring 1, making them unsuitable for wells of different sizes and exhibiting poor adaptability. To address this issue, a second spring 403 is fitted onto the outer wall of the fixing post 401, positioned between the end ring 1 and the stiffener plate 402. A baffle plate 404 is fitted onto one end of the fixing post 401, with a nut 405 threaded onto one side of the baffle plate 404. The stiffener plate 402 is elastically connected to the outside of the end ring 1 via the second spring 403, ensuring complete contact with the well wall in wells of different sizes. This guarantees that the casing remains centered and adapts to various well sizes, offering strong adaptability. Furthermore, the nut 405 allows for easy individual disassembly and replacement of any single stiffener plate 402.

[0028] Furthermore, the stiffener 402 is an outwardly protruding arc-shaped structure; the arc-shaped structure design can provide some elastic deformation and can form a good centering effect with the well wall. At the same time, the arc-shaped profile helps the downhole fluid to pass through and reduces flow resistance.

[0029] Traditional centralizers with 402 stiffeners typically have fixed, rigid contact, resulting in primarily sliding friction with the casing inner wall. This leads to severe wear, potentially causing scratches on the casing inner wall or centralizer failure. Especially in horizontal or highly deviated wells, sliding friction significantly increases the difficulty of running the centralizer downhole. For more information on this issue, please refer to [link / reference needed]. Figure 3 and Figure 4 The rolling unit 406 includes two fixing blocks 4061 fixed to the inner wall of the rib plate 402. A screw 4062 is fixed on the fixing block 4061. Both ends of the screw 4062 are fitted with fixing plates 4064 that fit against the inner wall of the rib plate 402. Nuts 4063 are also threaded to both ends of the screw 4062. Multiple rollers 4065 are rotatably connected between the two fixing plates 4064. The multiple rollers 4065 are respectively located in multiple through holes opened on the side wall of the rib plate 402. The rollers 4065 protrude from the surface of the rib plate 402 and contact the inner wall of the casing, converting sliding friction into rolling friction, greatly reducing wear and resistance, extending the service life of the centralizer and the casing, and improving the efficiency of going downhole.

[0030] Traditional locking structures may be cumbersome to operate or prone to loosening, especially under high pressure or vibration environments, where the risk of locking failure is high. For solutions to this problem, please refer to... Figure 5 The locking assembly 3 includes a fixed buckle 301 fixedly connected to one of the end rings 1 and two locking buckles 305 fixedly connected to the other end ring 1. A spring 302 is installed inside the fixed buckle 301. A pin 303 is movably connected to both ends of the spring 302. A lever 304 is fixedly connected to the pin 303. The lever 304 is located in the movable hole opened on the fixed buckle 301. One end of the pin 303 is inserted into the locking hole opened on the locking buckle 305. The spring 302 pushes the pin 303 to lock automatically. It can be quickly unlocked by lever 304. The operation is convenient and suitable for the needs of rapid installation downhole. The two locking buckles 305 cooperate with the pin 303 to provide a double fixing point, enhance the connection reliability, and prevent the end ring 1 from loosening under high pressure or rotation conditions.

[0031] Traditional stiffener 402 has a uniform width, which can easily lead to stress concentration at both ends. Especially in the casing diameter reduction section, the ends of stiffener 402 are prone to deformation or breakage due to extrusion. To address this issue, the width of stiffener 402 is gradually reduced from the middle to both ends. The width gradient structure allows the middle of stiffener 402 to provide the main support force, while the gradually narrowing ends reduce edge stress concentration, improve extrusion resistance, and adapt to complex wellbore conditions.

[0032] It should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0033] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A casing centralizer characterized by: It includes two end rings (1) arranged symmetrically at the top and bottom. Each end ring (1) is composed of two half rings. One end of each half ring is hinged by a hinge (2), and the other end is fixed with a locking component (3). Multiple rib plate components (4) arranged in a ring array are fixed between the two end rings (1). The stiffener assembly (4) includes a fixed post (401) fixed to the outer wall of two end rings (1), a stiffener (402) is installed on the two fixed posts (401), and a rolling unit (406) is installed on the inner side of the stiffener (402) near the middle position, the rolling unit (406) protruding from the surface of the stiffener (402).

2. The casing centralizer of claim 1, wherein: A spring 2 (403) is sleeved on the outer wall of the fixed column (401) between the end ring (1) and the stiffener (402). A baffle (404) is sleeved on one end of the fixed column (401), and a nut (405) is threaded onto the fixed column (401) on one side of the baffle (404).

3. The casing centralizer of claim 1, wherein: The stiffener (402) is an outwardly protruding arc-shaped structure.

4. The casing centralizer of claim 1, wherein: The rolling unit (406) includes two fixing blocks (4061) fixed to the inner wall of the rib plate (402). A screw (4062) is fixed on the fixing block (4061). Both ends of the screw (4062) are fitted with fixing pieces (4064) that fit against the inner wall of the rib plate (402). Nuts (4063) are also threaded to both ends of the screw (4062). Multiple rollers (4065) are rotatably connected between the two fixing pieces (4064), and the multiple rollers (4065) are respectively located in multiple through holes opened on the side wall of the rib plate (402).

5. The casing centralizer of claim 1, wherein: The locking assembly (3) includes a fixed buckle (301) fixed to one of the end rings (1) and two locking buckles (305) fixed to the other end ring (1). A spring (302) is installed inside the fixed buckle (301). The two ends of the spring (302) are respectively fixed to pins (303) that are movably connected inside the fixed buckle (301). A lever (304) is fixed to the lever (303). The lever (304) is located in the movable hole opened on the fixed buckle (301). One end of the lever (303) is inserted into the lock hole opened on the locking buckle (305).

6. The casing centralizer of claim 1, wherein: The width of the stiffener (402) gradually decreases from the middle to both ends.

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